1. Field of the Invention
This invention relates to a multiple stage tube forming mill in which a plurality of rolling mechanisms are mounted on trucks. The trucks are set on rails, which are laid directionally crossing the material feeding line at right angles thereto. The rolling mechanisms are positioned on the material feeding line while rolling the coil material and are situated at other positions on the rails while the rolls are being set or adjusted or while the rolling mechanism stand by. More particularly, this invention relates to a tube forming mill in which a portion of the rails, that crosses the material feeding line, is formed as unit rails. These unit rails, together with a frame, can be moved vertically by operation of an elevating mechanism to set the truck on a fixing mechanism, in which the rollers can be assembled into or disassembled from the rolling mechanism, and in which the vertical drive shaft of the rolling mechanism can be brought into or out of engagement with the driving mechanism, which is disposed under the unit rails by lifting or lowering the connector arranged on the upper part of the driving mechanism.
2. Description of the Prior Art
As shown in FIG. 1, the conventional tube forming mill 1, which has been widely used is almost immovable once it has been positioned with respect to material feeding line. Therefore, in rolling the material into different shapes, it is a conventional practice to replace the rolls (not shown) which are mounted on rotating shafts 6. The shafts extend sideward, by means of universal joints, from bevel gear mechanism 4 which are connected in series to the motor 2 through the reduction gear 3. Alternatively, a whole stand, with several pairs of rolls is replaced.
During the replacement operation, the rolling process must be stopped. Furthermore, the conventional device is characterized several disadvantages in that that it requires skills of a high level and takes a substantial period of time to replace the rolls or the stand.
Moreover, the conventional devices, whether they be of the universal joint type as shown in FIG. 1, the link gear type or direct-couple type, are provided with a driving mechanism 8 located on the side of one roll stand 7, so that the device as a whole is large and occupies substantial floor space. This lowers the efficiency of the replacement and increases the cost thereof.